Kevin got a question the other day: “When you’re cutting with a plasma cutter, can you go too fast? How do you judge the correct speed for cutting?”

There are a couple of things you really want to keep in mind when you’re using a plasma cutter.

One, of course, is just to make sure you’re about an eighth of an inch or so above your metal – that’s a good height to start with. Then, as you start moving along and making your cut, watch for sparks coming along the top of the metal. You’re also going to try to watch the arc below the metal.

Kevin shows a piece of half inch steel plate. He’s going to start on one side of the metal and make a cut across it, going too fast. Watch the arc coming out of the bottom. He cuts the steel, and you can see the arc bend forward, then back.

When you’re going too fast like that, you’re going to get a really ragged cut. It’s just going to look awful.

If you’re cutting really, really too fast, sparks will actually come out on the top of the metal, because you’re not cutting all the way through the bottom. You’re basically just gouging the metal. Kevin turns the plasma cutter back on.

He cuts across the piece of metal again going even faster. This time sparks shoot out across the top of the steel plate. Very, very little of the arc goes down under the metal. As Kevin shows, the cut never even came through the other side.

So Kevin hopes that answers the question.

Before you go, you might want to stick around for a moment to see Kevin struggle to define “bad” ….

See this video now ….